In recent years, due to growing global energy needs, sources of energy alternative to fossil fuel have gained significant popularity. Utilization of wind turbines for converting wind power to electrical power is among one of the areas of the alternative energy developments. A wind turbine facility, also commonly referred to as a wind farm, includes a large number of wind turbines. Each wind turbine generates localized electrical power in the form of electric current that is integrated on to an electric grid of the wind turbine facility. The electrical power that is generated by the wind turbine facility is placed on to a regional electric grid.
Traditionally, each wind turbine includes a tower, a series of blades mounted on to a hub, a gear box that is mechanically coupled to the hub, an electric generator that is mechanically coupled to the gear box, a yaw controller for adjusting the direction with which the blades are facing the incident wind, control systems for controlling the electric generator and the yaw controller, and electrical components for interfacing the electric generator to the electric grid of the wind turbine facility. The yaw controller aligns the direction of the wind turbine blades to achieve the highest rotational speed for the blades against a given incident wind. Some of the above mentioned components, such as the hub which is mounted to the blades, the gear box, the electric generator, and the yaw controller are positioned atop the tower. Some of these components, e.g., the electric generator, are heavy. As a result, towers are required to be built in a manner as to support the weight of these components. Further, due to the heavy weight of these components, the yaw controller includes powerful components, e.g., a heavy-duty electric motor for changing the alignment of the blades. Also, due to the heavy weight of these components, the rate at which the yaw controller can adjust the direction of the blades may be slow, making the wind turbine unable to react to an often changing wind direction.
In addition, the electrical power that is generated at the electric generator is in an unregulated form, i.e., varying voltage amplitude and frequencies at varying current levels, in response to the fluctuation of the incident wind. Therefore, electrical power components are required to transform the fluctuating form of the electrical power to a regulated form, i.e., a nearly constant voltage amplitudes sand frequencies at varying current levels. Even with these electrical power components, the generated electrical current placed on transmission lines of the grid of the wind turbine facility may include power flicker which can manifest, e.g., into a visible change in brightness of a lamp due to rapid fluctuations in the voltage. In addition, electric power losses are realized in the process of converting the unregulated form of electric power to the regulated form.
Also, as mentioned above, each wind turbine in the wind turbine facility generates power locally to the wind turbine. The generated power from each wind turbine must be integrated on to the grid of the wind turbine facility. This integration requires costly electrical power components and advanced controllers to regulate and synchronize the electrical power that is generated by each wind turbine.
Therefore, an efficient way to transform wind power to electrical power is needed in the wind turbine facility that can control and operate each wind turbine, integrate power that is generated by each wind turbine into a central generation unit, and reduce flicker on transmission lines that connect the grid of the wind turbine facility to the regional grid.